add edit state for todo items
save updates to Todos
deleting a todo model
use templates to show different lists of TODOs, including just Active ones
Revert "use templates to show different lists of TODOs, including just Active ones"

This reverts commit ccaac657616a7d284ea8593af62630a2477701b6.
Revert "Revert "use templates to show different lists of TODOs, including just Active ones""

This reverts commit d2d0f10fe5ab3093f14da8a2aead815ae7b348b5.
Revert "use templates to show different lists of TODOs, including just Active ones"

This reverts commit ccaac657616a7d284ea8593af62630a2477701b6.